JPH07251520A - Printer - Google Patents

Abstract

PURPOSE:To always ensure good printing quality at the time of continuous printing by counting the number of heating elements applied by a printing control means and reducing applied energy in a predetermined reduction rate with respect to the count value. CONSTITUTION:A tape printer is equipped with a freely detachable tape receiving cassette CS and a thermal head 15 is vertically provided at a position where a laminated film 7 and a printing ribbon 9 are superposed one upon another. At the time of use, when the printing key of a keyboard is pushed and the command of the start of printing is issued, the number of heating elements to which a current is supplied during the period from the start of printing to the completion thereof is counted with the elapse of time by a number-of-dot counter and a value to which the number of dots of this time is added is newly set to the counter. The number N of dots is compared with the judged number M of dots and, in the case of N > M, a value wherein a subtraction current supply time is subtracted from a current supply time is set as a new current supply time and, when the new current supply time becomes shorter than a first comparison current supply time, the second judged number of dots and a second subtraction current supply time are set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a thermal head.

[0002]

2. Description of the Related Art It is generally known that when continuous printing is repeated in a printing apparatus, the temperature of the thermal head draws an ascending curve as shown in FIG. 7 due to heat accumulation. For this reason,
Ideally, the applied energy to be applied to the heating element of the thermal head is determined so that the heating element always has a constant printing energy. Specifically, it is ideal to apply a value obtained by subtracting the energy of the heat accumulated in the thermal head from the constant printing energy required for printing.

Conventionally, in a printing apparatus having a thermal head, which gives a constant applied energy when continuously printing, the energy stored in the thermal head is not taken into consideration. In some cases, the print quality was deteriorated due to excess and crushed printed characters and bar codes. In order to solve such a problem, for example, a printing apparatus has been proposed in which dot densities are cumulatively counted and the energization time to all the heating elements is shortened based on the counting result.

[0004]

However, in such a printing apparatus, as shown in the time chart of FIG. 7, since the number of dots is counted and the energization time is lowered at a constant rate, the printing start is started. Although the print quality is satisfied for a while (dot number t) after that, there is a problem that blurring occurs when continuous printing is repeated after the dot number t has elapsed. This is because the actual applied energy is insufficient with respect to the ideal applied energy by the amount of energy in the shaded area shown in FIG. 7, so that the predetermined printing energy is not reached even when combined with the energy stored in the thermal head. to cause.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a printing apparatus capable of constantly obtaining good printing quality in continuous printing.

[0006]

In order to solve the above problems, the printing apparatus according to claim 1 selectively applies the applied energy to a plurality of heating elements arranged in a row in the print head, as shown in FIG. Then, by continuously forming lines to be printed at once by the print head, the print control means for forming a predetermined print pattern on the print medium, and the applied energy depending on the heat accumulation of the print head. In a printing apparatus provided with a reduction control unit for controlling reduction, the reduction control unit counts the number of heating elements applied by the printing control unit, and the applied energy with respect to the number counted by the counting unit. A reduction unit that reduces the predetermined reduction rate, and a reduction rate changing unit that changes the predetermined reduction rate to a smaller value as the applied energy decreases, Characterized by comprising.

According to a second aspect of the present invention, there is provided the printer according to the first aspect, wherein the reduction rate changing unit is configured such that when the applied energy in the reduction unit is equal to or less than a preset comparison value, The predetermined reduction rate is changed to a small value.

According to a third aspect of the present invention, there is provided the printer according to the first or second aspect, wherein the predetermined reduction rate or the comparison value has a print medium as a determining factor.

[0009]

In the printing apparatus according to the present invention, the printing control means selectively applies the applied energy to the heating element of the printing head to continuously form a line printed at one time by the printing head. Forming a predetermined print pattern on the print medium. At this time, the applied energy is
The reduction control means controls the reduction according to the heat accumulated in the print head. That is, the counting unit counts the number of heat generating elements applied by the print control unit, and the reducing unit reduces the applied energy at a predetermined reduction rate with respect to the count number. The predetermined reduction rate is changed to a smaller value by the reduction rate changing unit as the applied energy becomes smaller. This is to cope with the fact that the heat storage amount of the print head initially sharply increases, but the heat dissipation and heat storage of the print head gradually oppose each other and the increase rate becomes smaller, so the increase rate becomes smaller. This allows
The reduction rate can be changed so that the sum of the applied energy and the heat storage amount of the print head becomes substantially constant.

In the printing apparatus according to the second aspect, the reduction rate changing unit changes the predetermined reduction rate to a small value when the applied energy in the reduction unit becomes equal to or less than the preset comparison value.
Thereby, the reduction rate can be changed so that the sum of the applied energy and the heat storage amount of the print head becomes substantially constant.

According to another aspect of the printing apparatus of the present invention, the predetermined reduction rate or the comparison value is determined by the print medium. The print medium means the type of print ribbon.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an English-only tape printer capable of printing a large number of characters such as alphabetic characters and symbols and bar codes on a printing tape. 2 is a perspective view of the tape printer, FIG. 3 is an explanatory view showing the inside of the main body frame, and FIG. 4 is a block diagram of a control system.

As shown in FIG. 2, a keyboard 3 is arranged in the front part of the main body frame 2 of the tape printer 1, a printing mechanism PM is arranged in the main body frame 2 behind the keyboard 3, and Immediately behind the keyboard 3, a liquid crystal display (LCD) 22 capable of displaying characters and symbols is provided. Further, a release button 4 for opening the cover frame 6 when the tape storage cassette CS mounted on the printing mechanism PM is attached / detached is provided immediately behind the LCD 22, and a printing tape is provided on the left side of the cover frame 6. A cutting operation button 5 for manually cutting 19 is provided.

On the keyboard 3, character keys for inputting alphabets, numbers, symbols, etc., space key, return key, line feed key, cursor movement key for moving the cursor key to the right or left, and printing. A size setting key for arbitrarily setting the character size, and the arbitrary character size is 16, 24, 32, 48, 64, 96
6 character size keys for setting the dot size of, the automatic setting key for automatically setting the character size to be printed according to the tape width or the number of lines of the printing tape 19, the print key for instructing printing, and various setting processes. The execution key to exit
A power key for turning the power on and off is provided.

Next, the printing mechanism PM will be briefly described with reference to FIG. 3. A rectangular tape storage cassette CS is detachably attached to the printing mechanism PM, and the tape storage cassette CS is transparent. Laminating film 7
The tape spool 8 around which is wound, the ribbon supply spool 10 around which the print ribbon 9 is wound, the take-up spool 11 around which the print ribbon 9 is wound, and the double-sided tape 12 having the same width as the laminate film 7 are peeled off. A supply spool 13 wound with paper as the outside and a joining roller 14 for joining the laminate film 7 and the double-sided tape 12 are rotatably provided. The double-sided tape 12 is
An adhesive layer is formed on both sides of the base tape, and release paper is attached to the adhesive layer on one side of the base tape.

The laminated film 7 and the printing ribbon 9
A thermal head 15 is erected at a position where and overlap,
The platen roller 16 that presses the laminate film 7 and the print ribbon 9 against the thermal head 15, and the feed roller 17 that presses the laminate film 7 and the double-sided tape 12 against the joining roller 14 to create the printing tape 19 are the main body. Support 18 pivotally attached to the frame 2
It is rotatably pivoted to. This thermal head 15
, A heating element group consisting of 128 heating elements is vertically arranged in a row.

Therefore, when the tape feed motor 47 (see FIG. 4) is driven in the predetermined rotation direction, the joining roller 14 and the take-up spool 11 are driven in synchronization with each other in the predetermined rotation direction to energize the heating element group, A predetermined heating element generates heat and the print ribbon 9 is thermally transferred. As a result, characters and barcodes are printed on the laminated film 7 by a plurality of dot rows, and the laminated film 7 is tape-fed in the tape feeding direction A as the printing tape 19 in a state where the double-sided tape 12 is joined. , As shown in FIG.
It is sent out of the body frame 2. The printing mechanism P
For details of M, refer to JP-A-2-106555.

Next, the manual cutting device 30 for cutting the printing tape 19 will be briefly described with reference to FIG. 3. A plate-shaped auxiliary frame 31 is erected right inside the main body frame 2. The fixed blade 32 is attached to the auxiliary frame 31.
Is fixed upwards. An operation lever 34 extending in the front-rear direction is attached to the pivot shaft 33 fixed to the auxiliary frame 31.
Is rotatably supported near the front end of the
A movable blade 35 is attached so as to face the fixed blade 32 at a portion corresponding to the front side of the pivot shaft 33.
Further, the rear end portion of the operation lever 34 is provided with the cutting operation button 5
The operating lever 34 is always located below the movable blade 35.
Is elastically biased by a spring member (not shown) in a direction away from the fixed blade 32. Further, the operation lever 3 is pushed to the front end of the operation lever 34 by pressing the cutting operation button 5.
A disconnection switch 41 is attached to detect that 4 has rotated for disconnection.

After printing on the printing tape 19,
Since the printing tape 19 extends between the fixed blade 32 and the movable blade 35 and extends outside the main body frame 2, when the cutting operation button 5 is pressed downward, the movable blade 35 is moved via the operation lever 34. These two blades 3 are brought close to the fixed blade 32.
At 2, 35, the printing tape 19 is cut.

Here, as the printing tape 19 which is fed from the tape storage cassette CS, the tape width is 6 mm and 9 mm.
There are 5 types available: mm, 12mm, 18mm, 24mm. Further, for each tape width, the color of the base tape forming the double-sided tape 12 (hereinafter, abbreviated to the color of the double-sided tape 12 at the end. The color of this base tape is the ground color of the tape) and the printing ribbon 9. The ink color of "black",
Plural types of tape cassettes prepared by arbitrarily combining "red", "blue", "yellow" ... "white" are prepared.

There are two types of the above-mentioned print ribbons 9, a resin-based ink ribbon represented by "black" color and a wax-based ink ribbon represented by "gold" color. An instant lettering cassette (not shown) is prepared as a type different from the tape storage cassette CS. In this instant lettering cassette, a long retransfer sheet around which a tape spool is wound is stored in place of the laminate film 7 in the same cassette body as the tape storage cassette CS, and a printing ribbon is also used. An ink ribbon for instant lettering (hereinafter referred to as “ink ribbon for lettering”) is stored in place of 9, but the double-sided tape 12 is not stored. When printing is performed using this instant lettering cassette, characters are printed on the retransfer sheet by the ink ribbon for lettering. Since the ink of the ink ribbon for the above-mentioned letter-letter contains a pressure-sensitive adhesive, etc., the printing surface of the retransfer sheet is placed on a transfer surface such as a desk or paper, and the back surface (non-print surface) 2) is rubbed with a hard material, the ink printed on the retransfer sheet is transferred onto the transfer surface.

As described above, the printing ribbon 9 accommodated in the tape accommodating cassette CS is composed of a wax ink ribbon, a resin ink ribbon, and an ink ribbon for lettering.
There are types. Then, on the bottom wall of these tape storage cassettes CS, in order to detect any of the above-mentioned five types of tape width, the color and type of the first projecting piece 20 and the printing ribbon 9 in which three projecting claws are combined. Each of the second projecting pieces 21 is a combination of at least five projecting pieces for detecting the. Then, on the main body frame 2, a tape width sensor 43 (see FIG. 4) that detects the tape width from the state of the projecting piece of the first projecting piece 20 and the print ribbon 9 from the state of the projecting piece of the second projecting piece 21. Ribbon sensors 44 (see FIG. 4) for detecting the color and the type are respectively attached.

Further, a cassette switch 42 (see FIG. 4) is provided on the main body frame 2 in order to detect that a plurality of types of tape storage cassettes CS are selectively mounted.
Is attached. Next, the control system of the tape printer 1 is configured as shown in the block diagram of FIG.

Input / output interface 50 of controller C
Includes a keyboard 3, a disconnection switch 41, a cassette switch 42, a tape width sensor 43, a ribbon sensor 44, and a display controller (LCDC) having a video RAM 24 for outputting display data to a liquid crystal display (LCD) 22. ) 23, a thermistor 46 for determining the environmental temperature, a drive circuit 48 for driving the thermal head 15, and a drive circuit 49 for driving the tape feed motor 47, respectively.

The control device C includes a CPU 52 and this CPU.
Input / output interface 50, CGROM 53, ROM 5 connected to 52 via a bus 51 such as a data bus
4, 55 and RAM 60. CGR
In the OM 53, dot pattern data for display is stored in association with code data for each of a large number of characters.

ROM (dot pattern data memory) 5
In FIG. 4, dot pattern data for printing is classified for each typeface (Gothic typeface, Mincho typeface, etc.) for each of a large number of characters for printing characters such as alphabetic characters and symbols, and for each typeface. 7 types (1
6, 24, 32, 48, 64, 96 and 128 dot sizes) are stored in association with the code data.

In the ROM 55, the display controller (LCDC) 2 is associated with code data of characters such as characters, numbers and symbols input from the keyboard 3.
Display drive control program for controlling 3 and print buffer 6
A print drive control program for sequentially reading the data of No. 4 to drive the thermal head 15 and the tape feed motor 47,
A control program for tape printing control, which will be described later and is unique to the present application, is stored.

The text data 61 input from the keyboard 3 is stored in the text memory 61 of the RAM 60. Text pointer (this content is the pointer value TP) 6
2 stores one address of the text memory 61. The print character size memory 63 stores data of the character size used for the set printing. The print buffer 64 stores print dot pattern data of a plurality of characters and symbols as print data.

Next, the print control process performed by the controller C of the tape printer 1 will be described with reference to the flowchart of FIG. When a print key provided on the keyboard 3 is pressed to start printing, the dot number counter N is first initialized (cleared in this embodiment), and the determination dot number M is set to the first determination dot number M1. A predetermined energization time T1 is set to the energization time T, a first subtraction energization time Ts1 is set to the subtraction energization time Ts, and a first comparison energization time Tx1 is set to the comparison energization time Tx as a comparison value (S100). The dot number counter N counts the number of heating elements energized from the start of printing to the end of printing over time, that is, the number of dots is accumulated. The predetermined energization time T1 is a value set in advance according to the color type of the print ribbon, and for example, black has a longer energization time T1 value than white. The first subtraction energization time Ts1 and the number of determination dots M1 are set so that the reduction rate Ts1 / M1 substantially matches the slope of the tangent line at the point P in the graph of FIG.

Subsequently, a value obtained by adding the present dot number NL to the dot number counter N is newly set in the dot number counter N (S110). Here, the number of dots NL at this time refers to the number of heating elements to be energized this time in the heating element group. Then, the dot number counter N and the determination dot number M
And (S120), and if it is less than the determination dot number M (YES in S120), the process proceeds to S160.

On the other hand, if the number of dots is equal to or more than the determination dot number (S120
NO), a value obtained by subtracting the subtraction energization time Ts from the energization time T is newly set as the energization time T, and the dot number counter N is reset (S130). It is empirically known that the reduction control is executed by storing a predetermined amount of heat in the thermal head 15 when the determination dot number M is reached. This is because good energy is not applied to the heating element and good printing quality is maintained.

Subsequently, the energizing time T and the comparative energizing time Tx are compared (S140), and the energizing time T is compared to the comparative energizing time Tx.
If so (NO in S140), the process proceeds to S160. On the other hand, if the energization time T is smaller than the comparison energization time Tx (YES in S140), the determination dot number M is the second determination dot number M2, the subtraction energization time Ts is the second subtraction energization time Ts2,
The second comparative energizing time Tx2 is set to the comparative energizing time Tx (S150). The second comparison energization time Tx2 is the second subtraction energization time Ts2 from the minimum energization time Tm that is the minimum required for printing.
It is set to a value smaller than the value obtained by subtracting. The second comparison energization time Tx2 does not correspond to the comparison value in the present invention. Further, the second subtraction energization time Ts2 and the second determination dot number M2 are set so that the reduction rate Ts2 / M2 substantially matches the inclination of the tangent line at the point Q in the graph of FIG.

Next, it is determined whether the energization time T is longer than the minimum energization time Tm required for printing (S160),
If the energization time T is larger than the minimum energization time Tm (S1
If YES at 60), printing for one line is executed at the energization time T (S180). On the other hand, if the energization time T is equal to or less than the minimum energization time Tm (NO in S160), the energization time T
The minimum energization time Tm is set to (S170), and printing for one line is executed at the energization time T (S180). As described above, since the minimum energization time Tm is set as the lower limit value, there is no fear that the printing will be faint when the energization time T is excessively reduced. Here, one line means an area in which the heating element groups arranged in a row print at one time.

After that, it is judged whether or not the printing of all lines is completed (S190), and if not completed (S190).
If NO at 190), the processing of S110 and thereafter is repeatedly executed. If it has ended (YES in S190), this processing ends. The second comparative energization time Tx2 is the minimum energization time Tm.
Since it is set to a value smaller than the value obtained by subtracting the second subtraction energization time Ts2 from
Even if the new energization time T is calculated by subtracting S130 with the value set, the energization time T will not become smaller than the second comparison energization time Tx2. Therefore, once S
After passing through 150, it will be constantly judged as "NO" in S140.

FIG. 6 shows a time chart when the above print control process is executed. As you can see from this figure,
Since the applied energy approaches the curve of ideal energy,
The printing energy, which is the sum of the amount of heat stored in the thermal head 15 and the applied energy, is substantially constant. Therefore, there is no fear that the printing energy will be excessive and the characters or the like will be crushed, or that the printing energy will be insufficient and the characters or the like will be blurred.
The effect that constantly good print quality can be ensured is obtained. Such an effect is more clearly exhibited when printing a barcode. That is, the bar code reader cannot be recognized when the printed bar code is faint, but such a problem can be prevented by the control of this embodiment.

Here, the correspondence between the components of this embodiment and the present invention will be clarified. The thermal head 15 of this embodiment
Corresponds to the print head of the present invention, and the CPU 52 corresponds to the print control means and the reduction control means. In addition, S11 of FIG.
The processing of 0 to S170 is the same as the processing of the reduction control unit, and S180
Corresponds to the processing of the print control means. Further, S110 corresponds to the process of the counting unit, S120 and S130 to the process of the decreasing unit, and S140 and S150 to the process of the decreasing rate changing unit. Further, the energization time T corresponds to the applied energy, and the subtraction energization time Ts / the number of determination dots M corresponds to the reduction rate.

It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be carried out in various modes without departing from the technical scope of the present invention.
For example, in the above-described embodiment, the control is performed in two steps with the first comparison energization time Tx1, which is a comparison value, as a boundary, but if the control is performed in multiple steps, the curve of ideal energy can be more approximated. For example, the reduction rate is Ts1 / M1 when the energization time T is T1 to Tx1, and the reduction rate is Ts2 / M when the energization time T is Tx1 to Tx2.
2. In the case of Tx2 to Tx3, if the reduction rate is Ts3 / M3, ..., The effect of the above embodiment can be further enhanced. At this time, it goes without saying that the reduction rate is set smaller as the energization time becomes shorter.

Further, the first and second determination dot numbers M1 and M
The second, first and second subtractive energizing times Ts1 and Ts2 and the first and second comparative energizing times Tx1 and Tx2 may be set according to the type of print ribbon. For example, the reduction rate Ts / M becomes smaller in the order of “gold” print ribbon> ink letter ribbon for imprinter> print ribbon of “black”, that is, wax ink ribbon> ink ribbon for letter ink> resin ink ribbon. By setting the first comparative energization time Tx1 to decrease in the order of "black" print ribbon>"gold" print ribbon> ink ribbon for lettering, it is possible to absorb the difference in print energy depending on the type of print ribbon, and each print It is possible to obtain the same print quality as the ribbon.

The predetermined energization time T1 may be set depending on whether the object to be printed is a character or a bar code. For example, in the case of a character, the printing area is smaller than that of a bar code, so a large energization time may be set.

[0040]

As described in detail above, according to the printing apparatus of the first to third aspects, the applied energy applied to the heating element is appropriately changed according to the heat accumulation of the print head, so that the continuous printing is performed. It is possible to constantly obtain good print quality. According to the printing device of claim 3,
Since the applied energy is changed depending on the type of print medium, a better print quality can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of the present invention.

FIG. 2 is a perspective view of a tape printer.

FIG. 3 is an explanatory view showing the inside of the main body frame.

FIG. 4 is a block diagram of a control system.

FIG. 5 is a flowchart of print control processing.

FIG. 6 is a time chart of print control processing.

FIG. 7 is a time chart of a conventional example.

[Explanation of symbols]

1 ... Tape printing device, 9 ... Printing ribbon, 15 ... Thermal head,
15a ... Heating element group, 19 ... Printing tape,
52 ... CPU, C ... control device,
N: Dot number counter, N
L: number of dots, PM: printing mechanism, T: energization time, T
m: minimum energization time, Ts: subtraction energization time,
Tx ・ ・ ・ Comparative energizing time,

Claims (3)

[Claims] 1. A print medium is formed on a print medium by continuously applying lines to a plurality of heating elements arranged in a line on the print head to continuously form lines to be printed by the print head at one time. In a printing apparatus including a print control unit that forms a predetermined print pattern and a decrease control unit that decreases the applied energy according to heat accumulated in the print head, the decrease control unit applies the print control unit. A counting unit that counts the number of generated heating elements; a reducing unit that reduces the applied energy with a predetermined reduction rate with respect to the number counted by the counting unit; and a predetermined reduction rate that decreases as the applied energy decreases. A printing device comprising: a reduction rate changing unit for changing the value to a small value. 2. The reduction rate changing unit changes the predetermined reduction rate to a small value when the applied energy in the reduction unit is equal to or less than a preset comparison value. The printing device according to 1. 3. The predetermined reduction rate or the comparison value is determined by a print medium as a determinant.
The printing device described.